Sound-reproducer.



No. 891,367. PATENTED JUNE 23, 1908. A. N. PIERMAN.

SOUND REPRODUGER. I ABPLIOATION nun F313. 2, 1907.

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Z? Z? JZW W tram M g UNITED STATES PATENT OFFICE.

ALEXANDER N. PI'ERMAN, OF NEWARK, NEW JERSEY, ASSIGNOR TO NEW JERSEY PATENT COMPANY, OF WEST ORANGE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SOUND-REPRODUCER.

Specification of Letters Patent.

Patented June 23, 1908.

Application filedFebruary 2, 1907. Serial K0 3555388 To all whom it may concern:

Be it known that I, ALEXANDER N. PIER- MAN, a citizen of the United States, and a Reproducers, of which the fol-lowing is a de son tion.

y invention relates to sound re roducers of the general t e disclosed and claimed in my applications erial No. 288,837, filed November 24,. 1905 and Serial No. 307,324, filed March 22, 1906, and has for its object the provision of means whereby improved results will be secured.

My invention consists'of an improved form of valve for var ing the rate of flow of elastic fluid through the ports which communicate with the resonating chamber, and an inrproved form of port for 006 crating with the valve referred to, as wil be hereinafter pointed out and claimed.

Reference is hereby made to the accompanyingdrawin of which Figure 1 is a I ottom plan view of a ort late to which one form of valve is app ied;

igs. 2,3 and 4 are sections u on lines 2.2, 3 3 and 4-4 respectively 0 Fig. 1; Fig. 5 is a bottom plan view of a port plate pro.- vided with a modified form of valve F113. .6 is a-section on line 6-6 of Fig. 5; Fig. 7 is a bottom plan on a smaller scale of a ort plate adapted to be used with either of t e valves illustrated or with any other valve which is adapted to vary the flow of elastic fluid through the ports in accordance with the vibrations of sound waves; Fig. '8 is an enlarged section on line 8-8 of Fig. 7 with a valve seated upon the ports-thereof; Fig. 9

is a plan" view of a modified form of port late; Fig. 10 is a section on line 1010 of ig. 9; Flg. 1 1 is a vertical section of a phonogra hic sound reproducer showing the rel ative ocations of the orted plate, valve, resonating chamber, sty us, etc, and Fig. 12 is a section on line 1212 of Fig. 5,

Referring to Fig. .1, the improved valve comprises a late 11", the greater portion of whose lengtli tongues 12, the number of which corres ends with the. number of ports with whic the valve is to cooperate. I have obtained favorable results b the use-of valves having three tongues o the relative proportions illustrated. The valve 11 when in use will,

is slotted to form parallel be secured to a' port plate 13 in any suitable manner, as'by means of screws '14 passing through openings in the plate 1 1 and threaded in the plate 13. The. plate 11 is weakened along a line adjacent the screws 14 by being cut away to form a transverse groove 15. The bottom of this groove is cut out through out its intermediate portion as shown at 16,

(Figs. 1, 2 and 3) so as to leave two thin narrow tongues 17 as the only connection between the main body of theplate 11 and that portion which is held by the screws 14. Secured to the free ends of the ton ues 12 is a transverse bar orbridge 18 w'hic serves to bind the tongues together and revent torsional movements thereof; valve plate flat and prevents separate or individual vibrations of the ton ues. The plate 11 and bar 18 are preferaby made of aluminum and are cemented to ether by shellac or other suitable material. A fiat spring 19 is secured at one end to the plate 11 by the middle screw 14 and presses with its free end up'onthe middle tongue 12. The point of contact of the free end of the spring may be either at the point shown in the drawing or the spring may be prolonged so as to rest upon that portion of the tongue 12 which is at the point of greatest ressure of the air stream which passes throng the ports, or it may even extend close to the free end of the tongue 12. This spring 19 is centered with respect to the tongue 12 and the tensionof the spring regulated by the adjusting screw 20 The tongue 12 is shown as hav-' ing a pin hole 21 for receiving the link 22 which connects the tongue 12 with the stylus lever 23.

The valve shown in Figs. 5 and 6 is some what similar to that of Figs. 1 to 4, but-differs therefrom in the she e of the transverse groove 15. In the va ve of Fig. 5 the metal It aso keeps'the is cut away immediately at the base of the tongues 12, see 12, so as to form a groove 32 with a sloping wall 33 which extends close to the ends of the ports through which the ispensed with and than that of said tongues so as to provide s )aces 25 for the escape of air passing through the ports 26. The port plate 13 of Figs. 1 to 6 is a flat plate having ports 26 out therethrough and the tongues 12 of the valve 11 restupon the flat surface of the plate 13 ad jac'e'nt the edges of the ports 26. IVith this construction the flow of air depends upon the width of the tongue 12 as'regards the port 26, that is, if the width of the tongue 12 is increased, other conditions being unchanged, the flow of air will be diminished; and also if the tongue 12 is not accurately centered with respect to the port 26 so that the overlap or bearing surface of the tongue is greater at one side of the port than the other, there will be an unequal flow of elastic fluid at the opposite sides o'fsaid tongue because more air'will escape from the side where there is the smaller amount of overlap. Such irregularities in flow produce defects in the sound reproduction.

Another reason why inaccurate centering of the tongues 12 produces defects in reproduction is because when the valve moves from an opento or toward a closed position the air between the tongues 12 and plate 13 acts as a cushion and in case the tongues are not properly centered, there will be a greater cushioning effect on one side than on the other which will tend to tilt or twist the tongue laterally and thereby prevent it from closing the port. It is therefore highly important, in constructing a sound reproducer with this type of valve plate, to use the greatest accuracy as to the width ofthe tongues 12 and slots 26 and as to the centering of the said tongues with respect to the said slots. In order to avoid the necessity for the extreme accuracy referred to, I prefer to cut away the portions of the ported plate which surround the ports 26, as shownin Figs. 7, 8 ahd 10, thus forming knife edges 27 surrounding each of the ports 26, upon which edges the tongues 12 are adapted to lie. These knife edges may be either sharp or slightly flattened. The cutaway portions of the plate 13 form channels 28 for the escape of the elastic fluid passing through the ports 26. It will be obvious that with. this construction the flow of fluid through the ports 26 will be independent of the wldth or centering of the ton ues 12.

In the plate of Figs. 9 and 10 the central portion 30 is of increased thickness and the ports 3]., having walls which converge towards their lower edges, form a series of funnels of considerable depth and with their upper edges in immediate juxtaposition.

These funnels amplify the sounds produced by the variations in flow of elastic fluid therethrough. The lower surface of the plate 29 is shown as being cut away to form channels 28 and knife edges 27 similar to those of Figs. '7 and 8.

Fig. 11 shows the preferrec of parts, when my invention is used for phonographic reproduction, although it is Having now described my invention, what I claim as new and desire to secure by Letters Patent, is as follows:

1. Ina sound reproducer, a valve consisting of a plate weakened along a line of flexure by a groove the bottom of which is cut through along part of its length, substantially as set forth.

2. In a sound reproduce'r, a valve consisting of a plate of elastic material formed with. parallel tongues and a transverse groove which forms a line of flexure, substantially as set forth.

3. In a sound reproducer, a valve consisting of a plate formed with tongues and a bridge across the ends thereof remote from the point of support of the plate, substantially as set forth.

4. In a sound reproducer, a flat plate provided with a port, the surface of said plate being cut away and sharpened adjacent the edges of said port to form knife edges, substantially as set forth.

5. In a sound reproducer, the combines tion of a flat plate provided with a set of ports the edges of which project to form knife edges and a valve consisting of a plate formed with tongues, said tongues resting against said knife edges to vary the extent of opening of said ports, substantially as set forth.

-6. In a sound reproducer, a member pro vided with a set of funnel shaped ports,- and means for varying the flow of elastic fluid therethrough, substantially as set forth.

7. In a sound reproducer, a plate formed with funnel-shaped ports, the edges of which are in immediate juxtaposition, substantially as set forth. r

8. In a sound reproducer, the combination of a body formed with resonating and equalizing chambers and ports connecting said chambers, said ports being-formed with Walls which converge from the resonating chamber toward the equalizing chamber, forming funnels of greater depththan width, substantially asset forth.

9. In a sound reprod'ucer, the combination of a plate having a port and a valve therefor consisting of a plate weakened along a line of flexure by a groove, said groove extending close to the edge of said port, substantially as set forth.

l arrangement 10. In a sound reproducer, a valve consai sisting of a plate formed with tongues and a transverse'groove which forms a line of fieX- ure, said groove extending to the base of said tongues, substantially as set forth.

sisting of a plate formed with tongues and a transverse groove which forms a line of fiexure, said groove extending to the base of i as set forth.

this 1st day of February 1907. ALEXANDER N. PIERMAN.

Witnesses:

DELOS HOLDEN, FRANK D. LEWIS;

In a sound reproducer, a valve con- It is hereby certified that in Letters Patent No. 891,367, granted June 23, 1908, upon the application of Alexander N. Pierman, of Newark, New Jersey, forv an improvement in Sound-Reproducers, an error'appears in the printed 'specificationjequiring correction, as follows: In line 105, page 1, the word partishou1d read port; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case'inthe Patent'Oflice.

' Signed and sealed this 6th day of October, A. D., 1908.

o; o. BILLINGS,

Acting Commissioner of Patents.

[SEAL] d tongues and increasing gradually in 10 depth as it leaves said tongues, substantially This specification signed and witnessed 

